A critical assessment of opioid treatment adherence using urine drug testing in chronic pain management.

OBJECTIVE: To determine the current status of performing urine drug tests (UDTs) for monitoring chronic pain therapy, with an emphasis on their use in opioid treatment and the need for improved physician education about UDTs.

RESULTS: Although opioids are commonly used in the treatment of chronic pain, their use is associated with an increased risk for drug abuse, addiction, diversion, and overdose in chronic pain patients. Thus, adherence with opioid therapy is central to optimal chronic pain management. Patient observation (ie, early refills, pill counts, etc.) is the least effective method of assessing opioid medication adherence. Urine drug tests, such as point-of-care (POC) tests and laboratory urine tests (LUTs) employing gas chromatography/mass spectrometry or liquid chromatography mass spectrometry and liquid chromatography tandem mass spectrometry, have recently been used. Point-of-care immunoassays are commonly used to assess treatment adherence, especially in primary care. However, POC tests are less specific and less sensitive than LUTs and are more likely to give false-negative or false-positive results, increasing the risk of excluding a patient from therapy due to an erroneous diagnosis. In contrast, LUTs provide quantitative measurement of a wider range of medications and their metabolites, and represent a more precise tool for monitoring drug adherence. They are, however, more difficult to interpret and more expensive. Physicians are generally unaware of the relative merits of POC tests and LUTs, their implementation, and interpretation of adherence data.

CONCLUSION: Despite the acknowledged utility of UDTs, there is a critical need for physician education on the use of different UDTs for adherence monitoring because early detection of opioid nonadherence is key to optimal chronic pain management.